- Author
- Celso Martinho, Ruskin Constant, Rui Figueira and Luís Duarte, Cloudflare
- Published
- August 6, 2026
- Kind
- Company product announcement and engineering post, with a benchmark table
- Original
- blog.cloudflare.com/kitesurf/
- Subject
- Harnesses and agent loops
- Themes
- Small means, Handing over control
What it is
Four Cloudflare authors announce Kitesurf as an option inside the Browser Run product. The post explains why they built a browser for agents. It also shows how the parts fit. It also says where Kitesurf works today and where it does not.
What it says
- The post says Chromium was built for humans. Giving every agent its own costs too much.
- Kitesurf has three main parts: the Engine, PageScript and PageRenderer, each on Workers.
- The team used AI agents for much of the build. The Web Platform Tests suite guided them.
- Kitesurf passes around 215,000 Web Platform Tests, with hundreds more each week.
- Across a 14-URL corpus, Kitesurf used 3 to 7 times less CPU and memory. Wall time was about 1.7 times slower.
- Design rules: fail to a blank frame, treat every page load as untrusted, stay stateless.
- Kitesurf cannot yet play video, render WebGL, pass bot challenges or hold long authenticated sessions.
What evidence it gives
The post gives a count of Web Platform Tests passed. It gives a table of median CPU, memory and wall time over a 14-URL corpus. It names sites that render correctly.
Interests and limits
Cloudflare sells Browser Run, and the post announces its own beta product. The benchmark is the company's own, over a small corpus with five runs. The diagrams, charts and demo images were not viewed, only the page text. The post says the source code is not yet open.